Each tire/wheel assembly of a model race car of the foregoing type customarily includes a substantially rigid wheel having a cylindrical rim. A foam rubber body encircles and is bonded to the outer cylindrical surface of the rim. A body of more dense tread rubber overlies and is bonded to the radially outer cylindrical surface of the foam rubber body. The foam rubber body of each tire/wheel assembly is subjected to severe stress during operation of the race car. When the car collides at high speeds with another car or a wall of the race track, the force of the impact can and frequently does cause chunks of the foam rubber material to be torn from one or both of the exposed opposite sides of the foam rubber body. Additionally, as the speeds attained by the cars increase, the "ballooning" type of radial displacement undergone by the rubber bodies, due to centrifugal force, is more likely to cause the foam rubber body to undergo internal separation and/or separation from the tread rubber body or the rim of the assembly. The foregoing undesirable occurrences shorten the useful life of the wheel assemblies and impair the performance of the cars.